Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<(td) class=""headerCovTableEntryLo"">([0-9.]+)\s?%<\/\1>"; string input = @" <head> <meta http-equiv=""Content-Type"" content=""text/html; charset=UTF-8""> <title>LCOV - .info.cleaned</title> <link rel=""stylesheet"" type=""text/css"" href=""gcov.css""> </head> <body> <table width=""100%"" border=0 cellspacing=0 cellpadding=0> <tr><td class=""title"">LCOV - code coverage report</td></tr> <tr><td class=""ruler""><img src=""glass.png"" width=3 height=3 alt=""></td></tr> <tr> <td width=""100%""> <table cellpadding=1 border=0 width=""100%""> <tr> <td width=""10%"" class=""headerItem"">Current view:</td> <td width=""35%"" class=""headerValue"">top level</td> <td width=""5%""></td> <td width=""15%""></td> <td width=""10%"" class=""headerCovTableHead"">Hit</td> <td width=""10%"" class=""headerCovTableHead"">Total</td> <td width=""15%"" class=""headerCovTableHead"">Coverage</td> </tr> <tr> <td class=""headerItem"">Test:</td> <td class=""headerValue"">.info.cleaned</td> <td></td> <td class=""headerItem"">Lines:</td> <td class=""headerCovTableEntry"">399</td> <td class=""headerCovTableEntry"">1019</td> <td class=""headerCovTableEntryLo"">39.2 %</td> </tr> <tr> <td class=""headerItem"">Date:</td> <td class=""headerValue"">2016-11-07</td> <td></td> <td class=""headerItem"">Functions:</td> <td class=""headerCovTableEntry"">22</td> <td class=""headerCovTableEntry"">67</td> <td class=""headerCovTableEntryLo"">32.8 %</td> </tr> <tr><td><img src=""glass.png"" width=3 height=3 alt=""></td></tr> </table> </td> </tr> <tr><td class=""ruler""><img src=""glass.png"" width=3 height=3 alt=""></td></tr> </table> <center> <table width=""80%"" cellpadding=1 cellspacing=1 border=0> <tr> <td width=""50%""><br></td> <td width=""10%""></td> <td width=""10%""></td> <td width=""10%""></td>"; foreach (Match m in Regex.Matches(input, pattern)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx